The \(3\times 3\)  squared mass matrix of CP-even neutral scalars reads
Here we follow the conventions and notation in Ref.[1]}.,
\({}\mathcal {M}^{2}=\left(\begin{array}{ccccc}\frac{A_{\lambda }^{2}}{1+x}+(M^{2}_{Z}-\lambda ^{2}\upsilon ^{2})\sin ^{2}2\beta & -\frac{1}{2}(M^{2}_{Z}-\lambda ^{2}\upsilon ^{2}) \sin 4\beta & - A_{\lambda }\lambda \upsilon \cos 2\beta \\* & M^{2}_{Z}\cos ^{2}2\beta +\lambda ^{2}\upsilon ^{2}\sin ^{2}2\beta & - A_{\lambda }\lambda \upsilon \sin 2\beta \frac{x}{1+x} \\* & *& \lambda ^{2}\upsilon ^{2}(1+x) \\\end{array}\right)\) 
